STANDLEY—STUDIES OF TROPICAL AMERICAN PHANEROGAMS, 439 
A REVISION OF THE GENUS WATSONAMRA. 
The name Pentagonia was applied by Bentham in 1844 to a rubi- 
aceous plant collected by Hinds in Panama, which he called Penta- 
gonia macrophylla. Unfortunately this generic name had been used 
twice before, Pentagonia having been applied by Ventenat in 1841 to 
a member of the Campanulaceae and Pentagonium by Schauer in 
1843 to an asclepiad. 
In the Kew Index, as well as in Dalla Torre and Harms’s Genera 
Siphonogamarum, Seemannia of Hooker? is cited as a synonym of 
Pentagonia, dating from 1848. Upon investigating this reference 
one finds that Seemannia was scarcely published here, Hooker merely 
saying in discussing Pentagonia pinnatifida,“ * * * should fu- 
ture observations discover marks sufficient to constitute of our present 
plant a new genus, I can not but wish it should have the name of its 
discoverer, Seemannia.” A genus of the Gesneriaceae was named 
Seemannia by Regel in 1855. 
The two works cited also list Megaphyllum Spruce as a synonym 
of Pentagonia, but this was cited by Baillon as a synonym,? hence is 
not published. It is not clear what the plant is to which Spruce ap- 
plied the name of Megaphyllum, for the writer has not found a cita- 
tion in literature of Spruce’s number mentioned by Baillon. 
Otto Kuntze, in 1891, finding the rubiaceous group to be without 
a name, designated it as Watsonamra, in honor of Dr. Sereno Wat- 
son. This is the name that apparently must stand for the genus. 
Heretofore six species of Pentagonia, or Watsonamra, have been 
described from Central America and northwestern South America. 
The recent collections of this genus in Panama comprise a more ex- 
tended series of specimens than has been brought together heretofore. 
Among the collections of Mr. Pittier and Mr. Williams the writer 
has found four plants that seem different from those already de- 
scribed. A plant from Costa Rica, distributed as Pentagonia wend- 
landi, also appears to be new. Thus the number of known species 
is increased to eleven. 
Watsonamra is remarkable because of the venation of the leaf 
blades, the tissue being finely lineolate between the reticulate veins. 
When a piece of the blade is broken, the fragments are held together 
by the fine white threads drawn from the striw. The genus is not 
peculiar in this respect, a few other members of the family exhibit- 
ing the same structure. It is remarkable, however, in containing the 
only members of the Rubiaceae which have pinnatifid leaves. 
*Lond. Journ. Bot. 7: 567. 1848. 
? Hist. Pl. 7: 456. 1880. 
